One of the serious side effects of anti-cancerous chemotherapy is the diminution of neutrophils in peripheral blood. Patients are therefore at risk of developing opportunistic infections.
Acute neutropenia (occurring over a few days) often develops when neutrophil use is rapid and production is impaired. Chronic neutropenia (lasting months or years) usually arises from reduced production or excessive splenic sequestration of neutrophils. Neutropenia may be classified as whether it arises secondary to factors extrinsic to marrow myeloid cells or whether an intrinsic defect appears to be present in the myeloid progenitors.
Drugs are one of the most common cause of neutropenia. The incidence of drug-induced neutropenia increases precipitously with age; only 10% of cases occur in children and young adults, and more than 50% occur in adults.
Management of acquired transient neutropenia characteristically associated with malignancies, myelo-suppressive chemotherapy, or immunosuppressive therapy differs whether they are congenital or chronic forms of neutropenia. Infections are the major cause of death in these patients, who must therefore be approached with a high index of suspicion. Early recognition and treatment of infections may be lifesaving. If the acute neutropenia is suspected to be drug-induced, all potentially offending drugs should be stopped immediately.
The role of antibiotic prophylaxis in non-febrile neutropenic patients remains controversial. Also, systemic antifungal prophylaxis is not recommended as a routine component in the management of neutropenic patients.
Using glucocorticoids, androgenic steroids, and vitamins to stimulate bone marrow to produce more neutrophils has not proved successful. Two growth factors (cytokines), granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF), are widely used to prevent fever and infections in patients with severe neutropenia (e.g, after bone marrow transplantation and intensive cancer chemotherapy). However, blood formula regeneration takes approximately two weeks, during which time the patient can still acquire infections. Moreover, the control of neutrophil traffic from bone marrow to blood with G-CSF and GM-CSF to reduce the risk of infections during chemotherapy exhibits adverse effects such as bone pain, abnormalities of liver dysfunctions and pleural and pericardial effusions.
Therefore, there is a need for new therapeutic drugs and a method of treatment that are more active and induce less side-effects thereby reducing the duration of neutropenia and increasing the survival rate of patients undergoing chemotherapy or being in immunosuppressive conditions. Such therapy for neutropenia treatment or prevention should be easy and safe to administer, self-limiting, and require few diagnostic tests to follow the course of treatment. Such therapy should be affordable. Such a therapy would reduce the health care costs. The patient should be able to take the treatment on an ambulatory basis, thereby reducing hospital visits while still enjoying a better quality of life. Such therapy should maintain the productivity of the individual.